Define two factor authentication for Postgresql Server

Hello,
I'm going to create two factor authentication for pgadmin server...
I'm using postgresql 9.4 with pgadmin III on Linux Mint 17.2 32bit...
I already have 1 password authentication but For better security, I just
want to force 2 of them. The authentication factors could be any
things(what user has,what user knows,where user is or what user is).
for example:
The first factor is "password(what user knows)" and the second is "USB
device(what user has)". I need to force Postgresql to check both for
authenticate user and connect him to the server. I send you a screenshot
from pgAdmin server authenticate screen and I'm going to implement 2 factor
authentication for this. I not talking about OS authentication. All
authenticate operation should operate from Postgresql.

I already try this for login into pgAdmin through password and USB:
I installed pamusb pakages :

sudo apt-get install pamusb-tools libpam-usb

Although I can add devices on my pamusb config file :
pamusb-conf --add-device MyDevice

and I can define pamusb users. I added this lines to pamusb config between
<users> tags :
<user id="postgres"> <device>MyDevice</device> </user>

My guess : I think I should write module in /etc/pam.d and edit pg_hba.conf
file to define login method for local users :
local all all pam pamservice=mypam
but I don't know how to write module to force both authentication methods
for this(both are required).

Any help would be appreciated...